Half-frame wide-angle lens

Abstract

The utility model discloses a half-format wide-angle lens, which comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens which are sequentially arranged from an object space to an image space, the object side surfaces and the image side surfaces of the fifth lens, the sixth lens, the seventh lens and the tenth lens are convex surfaces, the object side surfaces and the image side surfaces of the fourth lens, the eighth lens and the ninth lens are concave surfaces, the object side surfaces of the first lens, the second lens and the third lens are convex surfaces, and the image side surfaces of the first lens, the second lens and the third lens are concave surfaces. The eleventh lens element has a concave object-side surface and a convex image-side surface. According to the half-frame wide-angle lens, only 11 lenses are adopted, the effective focal length of the half-frame wide-angle lens is 12mm and the relative aperture of the half-frame wide-angle lens is 2 through the cooperation and mutual cooperation of the 11 lenses, and the cost is reduced under the condition that an ultra-large wide angle and better imaging quality are ensured.

Description

Technical Field

[0001] This utility model relates to the field of lens technology, and in particular to a half-frame wide-angle lens. Background Technology

[0002] With the rapid development of technology, optical imaging plays a crucial role in numerous fields such as photography, videography, security monitoring, and virtual reality. People's demands for image quality are constantly increasing, expecting lenses to capture high-resolution, wide-field-of-view, color-accurate, and highly adaptable images in various complex scenes. This is especially true in professional photography, panoramic monitoring, and immersive virtual reality experiences, where the performance requirements for lenses are even more stringent.

[0003] While existing APS-C wide-angle lenses can achieve ultra-wide angles while maintaining image quality, their overall cost is high, making them unsuitable for ordinary consumers. Therefore, it is necessary to design an APS-C wide-angle lens that offers ultra-wide angles and good image quality at a relatively lower cost. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a half-frame wide-angle lens.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This utility model provides a half-frame wide-angle lens, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, and an eleventh lens arranged sequentially from the object side to the image side. The object-side and image-side surfaces of the fifth lens, the sixth lens, the seventh lens, and the tenth lens are all convex, while the object-side and image-side surfaces of the fourth lens, the eighth lens, and the ninth lens are all concave. The object-side surface of the first lens, the second lens, and the third lens is convex and the image-side surface is concave, while the object-side surface of the eleventh lens is concave and the image-side surface is convex.

[0007] Furthermore, the first lens, the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the ninth lens, and the tenth lens all have positive refractive power.

[0008] Furthermore, the fourth lens, the eighth lens, and the eleventh lens all have negative refractive power.

[0009] Furthermore, the fourth lens and the fifth lens are cemented lenses.

[0010] Furthermore, the seventh lens and the eighth lens are cemented lenses.

[0011] Furthermore, the refractive indices of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, and the eleventh lens are greater than 0.594 and less than 2.4229.

[0012] Furthermore, the Abbe numbers of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, and the eleventh lens are greater than 20.38 and less than 82.108.

[0013] The beneficial effects of this invention compared to existing technologies are as follows: A half-frame wide-angle lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, and an eleventh lens arranged sequentially from the object side to the image side. The object-side and image-side surfaces of the fifth, sixth, seventh, and tenth lenses are convex, while the object-side and image-side surfaces of the fourth, eighth, and ninth lenses are concave. The object-side surface of the first, second, and third lenses is convex, and the image-side surface of the eleventh lens is concave, and the image-side surface of the eleventh lens is convex. This invention uses only 11 lenses, and through their coordination and cooperation, it achieves an effective focal length of 12mm and a relative aperture of 2 for a half-frame wide-angle lens, reducing costs while ensuring ultra-wide angle and good image quality.

[0014] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model, it can be implemented according to the contents of the specification. In order to make the above and other objectives, features and advantages of this utility model more obvious and easy to understand, the following are preferred embodiments, which are described in detail below. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the structure of a half-frame wide-angle lens provided for a specific embodiment of this utility model;

[0017] Figure 2 A longitudinal color difference diagram provided for a specific embodiment of this utility model;

[0018] Figure 3 MTF diagram provided for a specific embodiment of this utility model;

[0019] Figure 4 Optical distortion diagram provided for a specific embodiment of this utility model;

[0020] Figure 5 Dispersion diagrams provided for specific embodiments of this utility model;

[0021] Figure 6 A relative illumination diagram provided for a specific embodiment of this utility model.

[0022] Figure Labels

[0023] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Seventh lens; 8. Eighth lens; 9. Ninth lens; 10. Tenth lens; 11. Eleventh lens. Detailed Implementation

[0024] The technical solution of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0025] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0028] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0030] like Figure 1 As shown, this utility model embodiment provides a half-frame wide-angle lens, including a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, and an eleventh lens 11 arranged sequentially from the object side to the image side. The object-side and image-side surfaces of the fifth lens 5, the sixth lens 6, the seventh lens 7, and the tenth lens 10 are both convex surfaces, while the object-side and image-side surfaces of the fourth lens 4, the eighth lens 8, and the ninth lens 9 are both concave surfaces. The object-side surface of the first lens 1, the second lens 2, and the third lens 3 is convex and the image-side surface is concave, while the object-side surface of the eleventh lens 11 is concave and the image-side surface is convex.

[0031] Specifically, the structure of this half-frame wide-angle lens mainly consists of eleven lenses, which are arranged sequentially from the object side (the direction in which light enters) to the image side (the direction in which light exits).

[0032] Lenses 5 (5), 6 (6), 7 (7), and 10 (10): both their object-side surface (the side where light first enters) and image-side surface (the side where light exits) are convex. Convex lenses typically converge light rays; in optics, these lenses can converge light rays and change their direction of propagation, providing a basis for forming a clear image.

[0033] The fourth lens (4), the eighth lens (8), and the ninth lens (9): both their object-side and image-side surfaces are concave. Concave lenses cause light rays to diverge, resulting in better image formation.

[0034] The first lens 1, the second lens 2, and the third lens 3 have a convex object side and a concave image side. This lens structure combines some characteristics of convex and concave lenses. Depending on the specific radius of curvature and position, it can balance the convergence and divergence of light to a certain extent and adjust the light path.

[0035] The eleventh lens (11): Its object side is concave and its image side is convex. Its function in the lens system is to participate in the adjustment of the entire lens's imaging optical path through its unique effect on light, which will affect the propagation of edge light and the image quality.

[0036] This invention uses only 11 lenses. Through their cooperation and collaboration, it achieves a half-frame wide-angle lens with an effective focal length of 12mm and a relative aperture of 2, reducing costs while ensuring ultra-wide angle and good image quality.

[0037] In one embodiment, the first lens 1, the second lens 2, the third lens 3, the fifth lens 5, the sixth lens 6, the seventh lens 7, the ninth lens 9, and the tenth lens 10 all have positive refractive power; the fourth lens 4, the eighth lens 8, and the eleventh lens 11 all have negative refractive power.

[0038] Specifically, the first lens 1 has positive diopter and converges light. The second lens 2 also has positive diopter and works in conjunction with the first lens 1. The second lens 2 further converges light and adjusts the light propagation path to better meet the overall lens system design requirements. Although the third lens 3 has a concave image side, it still has a comprehensive light-converging effect due to its overall positive diopter. It can correct aberrations that may be produced by preceding lenses to a certain extent, especially spherical aberration that may occur after light passes through the first and second lenses 2. The fifth lens 5 has positive diopter and, as one of the lenses with positive diopter, plays an important role in converging and aberration correction in the light propagation path. The sixth lens 6 continues to converge light in the lens system, further enhancing the energy density of the light and providing more light for subsequent lenses. The seventh lens 7 has convex object and image sides and positive diopter. The ninth lens 9 also has positive diopter and can continue to adjust the convergence of light at the rear of the lens, enhancing control over peripheral light and ensuring that peripheral light is also accurately focused on the image plane. The tenth lens, 10, as a positive diopter lens, serves as a key component for the final converging rays, focusing the light more precisely onto the image plane to ensure high resolution in the final image. The fourth lens, 4, has negative diopter and concave object and image sides, allowing it to diverge light and balance ray distribution and correct aberrations within the lens system. The eighth lens, 8, also has negative diopter and concave object and image sides, fine-tuning the light beams to reduce excessive convergence after passing through preceding lenses, thus helping to reduce astigmatism. The eleventh lens, 11, has a concave object side and a convex image side, and also has negative diopter. At the very end of the lens assembly, it provides final adjustments to the light beams, balancing convergence and divergence.

[0039] In one embodiment, the fourth lens 4 and the fifth lens 5 are cemented lenses, and the seventh lens 7 and the eighth lens 8 are cemented lenses.

[0040] Optical Principles and Functions: The main purpose of cementation is to correct aberrations, especially chromatic aberration, by utilizing the optical properties of different lens materials. Because different materials have different refractive indices for different wavelengths of light, different colors of light have different focal lengths, resulting in chromatic aberration.

[0041] The combination of the low refractive index of the fourth lens (4) and the high refractive index of the fifth lens (5) allows light of different colors to converge better onto the same focal plane when passing through the cemented lens. This is achieved through the careful design of the curvature radius of the cemented surface and the lens material. For example, when shooting colorful scenes, such as flower exhibitions, this type of cemented lens can clearly display all colors of flowers, from red to purple, on the same plane, avoiding blurry color edges or color deviations caused by chromatic aberration and ensuring accurate color reproduction.

[0042] The seventh lens (7) and the eighth lens (8) are cemented lenses: This set of cemented lenses is mainly used to correct geometric aberrations, especially distortion. Barrel or pincushion distortion is prone to occur in wide-angle lenses. By combining the converging properties of the seventh lens (7) and the diverging properties of the eighth lens (8), and utilizing the optical effect of the cemented surface, the propagation path of light can be adjusted to correct the geometric shape of the image. For example, when shooting architecture, it ensures that the straight lines of buildings remain straight in the image, rather than appearing curved or distorted, thus guaranteeing the geometric accuracy of the image. When shooting interior scenes, it prevents furniture and other objects from appearing unrealistically shaped due to distortion, making the image more consistent with human visual perception.

[0043] The cemented lens elements of the fourth lens (4) and the fifth lens (5) significantly improve the ability to correct chromatic aberration. This allows light of different colors to be better focused on the same plane as it passes through the lens, ensuring color uniformity and accuracy throughout the image. For example, when shooting landscapes containing blue skies, white clouds, and green trees, the blue sky does not exhibit blurred blue edges, the leaves of the green trees are more vibrant and have sharper edges, the transitions between different colors are natural, and the overall color reproduction is high, improving the color quality of the image. The cemented lens elements of the seventh lens (7) and the eighth lens (8) effectively reduce the distortion problems common in wide-angle lenses. Whether shooting skyscrapers in a city or interior furniture, straight lines in the image remain straight, avoiding image distortion caused by lens distortion, resulting in more realistic images with geometric shapes that better match the actual scene, thus improving the geometric quality of the image.

[0044] In one embodiment, the refractive indices of the first lens 1, second lens 2, third lens 3, fourth lens 4, fifth lens 5, sixth lens 6, seventh lens 7, eighth lens 8, ninth lens 9, tenth lens 10, and eleventh lens 11 are greater than 0.594 and less than 2.4229. The Abbe numbers of the first lens 1, second lens 2, third lens 3, fourth lens 4, fifth lens 5, sixth lens 6, seventh lens 7, eighth lens 8, ninth lens 9, tenth lens 10, and eleventh lens 11 are greater than 20.38 and less than 82.108.

[0045] In this embodiment, the first lens 1 has a radius of curvature of 23.17 mm on the object-side surface and 14.66 mm on the image-side surface, a thickness of 2 mm, a refractive index of 1.62, and an Abbe number of 60.368. The second lens 2 has a radius of curvature of 1037 mm on the object-side surface and 5.38 mm on the image-side surface, a thickness of 2.5 mm, a refractive index of 1.094, and an Abbe number of 55.874. The third lens 3 has a radius of curvature of 3573 mm on the object-side surface and 50.55 mm on the image-side surface, a thickness of 2.06 mm, a refractive index of 1.9229, and an Abbe number of 20.88. The material is FDS1. The fourth lens 4 has a radius of curvature of 36.87 mm on the object-side surface and 45.05 mm on the image-side surface, a thickness of 1.2 mm, a refractive index of 1.094, and an Abbe number of 55.874. The fifth lens (5) has a radius of curvature of 45.05 mm on the object-side surface and 40.04 mm on the image-side surface, a thickness of 2.1 mm, a refractive index of 1.6477, and an Abbe number of 33.837. The sixth lens (6) has a radius of curvature of 14.8 mm on the object-side surface and 41.7 mm on the image-side surface, a thickness of 3.4 mm, a refractive index of 1.497, and an Abbe number of 81.608. The seventh lens (7) has a radius of curvature of 37.2 mm on the object-side surface and 17.8 mm on the image-side surface, a thickness of 3.7 mm, a refractive index of 1.497, and an Abbe number of 81.608. The eighth lens (8) has a radius of curvature of 17.8 mm on the object-side surface and 48.48 mm on the image-side surface, a thickness of 1.2 mm, a refractive index of 1.6364, and an Abbe number of 35.386. The ninth lens (9) has a radius of curvature of 27.16 mm on the object-side surface and 31.9 mm on the image-side surface, a thickness of 1.2 mm, a refractive index of 1.7283, and an Abbe number of 28.324. The tenth lens (10) has a radius of curvature of 31.9 mm on the object-side surface and 47.68 mm on the image-side surface, a thickness of 2.5 mm, a refractive index of 1.9004, and an Abbe number of 37.371. The eleventh lens (11) has a radius of curvature of 44.8 mm on the object-side surface and 67.22 mm on the image-side surface, a thickness of 2 mm, a refractive index of 1.094, and an Abbe number of 55.874.

[0046] To better understand the technical advantages of the lens in this application, such as Figures 2 to 6 As shown, where Figure 2 This diagram illustrates the longitudinal chromatic aberration, showcasing the lens's performance in this embodiment. The diagram provides a visual understanding of the lens's varying degrees of focus on different colors of light, thus allowing assessment of the lens's chromatic aberration control performance. Figure 2 It can be concluded that the lens of this application has good longitudinal chromatic aberration control in the embodiments, indicating that the lens has good consistency in focusing on different colors of light, effectively reducing the image color deviation problem caused by chromatic aberration. Figure 3This is a diagram of MTF (Modulation Transfer Function). MTF is used to measure the imaging quality of a lens for targets at different spatial frequencies. Figure 3 This shows the MTF values ​​of the lens at different spatial frequencies. A higher MTF value indicates that the lens can better convey the detail and contrast of an object. From Figure 3 It is known that the lens of this application has a high MTF value at different spatial frequencies, indicating that the lens has a strong ability to transmit object details and contrast, performs well in terms of resolution, and can meet the requirements of high-resolution imaging. Figure 4 This is a diagram of optical distortion. Figure 4 The chart on the right is a diagram of F-Tan (Theta) distortion. It can be seen from the chart that the maximum distortion is 1.4471%, which indicates that there is a certain degree of distortion in the optical system, but the overall degree of distortion is relatively small. Figure 4 The chart on the left is a field curvature diagram, which shows how the meridional field curvature and sagittal field curvature change with the field of view. Figure 5 The figure shows excellent axial color difference control. Figure 6 This is a relative illumination diagram, used to show the relative illumination of the lens under different fields of view. From Figure 6 It can be seen that the lens of this application has relatively stable relative illumination performance under different fields of view, which means that the light is distributed more evenly in the image and can provide relatively consistent brightness in different areas, thus ensuring the stability of image quality.

[0047] Through the combination of the aforementioned eleven lenses and precise parameter settings, this APS-C wide-angle lens achieves an effective focal length of 12mm. When shooting landscapes, architecture, and large scenes, it provides a very wide field of view, capturing more scene elements compared to ordinary lenses. For example, when shooting indoor panoramas, the entire room layout can be included in the frame without stitching or moving further back. The relative aperture of 2 means that this lens allows a large amount of light to enter, producing bright and clear images even in low-light environments, such as indoors or at dusk. When shooting night scenes, it captures more detail without causing the image to be dark and blurry due to insufficient light.

[0048] By carefully selecting the lens shape, using cemented lenses, and precisely setting the spacing, this lens effectively corrects various aberrations, including spherical aberration, chromatic aberration, coma, astigmatism, field curvature, and distortion. During shooting, sharpness is guaranteed at both the center and edges of the image, with accurate color reproduction, realistic geometry, and high image sharpness. For example, when shooting an image containing architecture, people, and natural scenery, the lines of the buildings are straight, the skin tones and clothing colors of the people are realistically reproduced, and the entire image is clear and sharp without noticeable blur or distortion.

[0049] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A half-format wide-angle lens characterized by comprising: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens are arranged in order from the object side to the image side, the fifth lens, the sixth lens, the seventh lens and the tenth lens are convex on both the object side and the image side, the fourth lens, the eighth lens and the ninth lens are concave on both the object side and the image side, the first lens, the second lens and the third lens are convex on the object side and concave on the image side, and the eleventh lens is concave on the object side and convex on the image side.

2. A half-format wide-angle lens according to claim 1, characterized in that The first lens, the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the ninth lens and the tenth lens all have positive refractive power.

3. A half-format wide-angle lens according to claim 1 or 2, characterized in that The fourth lens, the eighth lens and the eleventh lens all have negative refractive power.

4. A half-format wide-angle lens according to claim 1, characterized in that The fourth lens and the fifth lens are cemented lenses.

5. A half-format wide-angle lens according to claim 1 or 4, characterized in that The seventh lens and the eighth lens are cemented lenses.

6. A half-format wide-angle lens according to claim 1, characterized in that The refractive index of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens is greater than 0.594 and less than 2.4229.

7. A half-format wide-angle lens according to claim 1, characterized in that The Abbe number of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens is greater than 20.38 and less than 82.108.

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